Keeper for



UNITED STATES PATENT OFFICE.

ANDREW PATTERSON, OF BIRMINGHAM, PENNSYLVANIA, ASSIGNOR TO J. H. JONES,OF PITTSBURGH, PENNSYLVANIA.

KEEPER FOR LOCKS AND LATCHES.

Specification of Letters Patent No. 17,611, dated June 16, 1857.

To all whom 'it may concern.'

Be it known that I, ANDREW PATTERSON, of the borough of Birmingham,county of Allegheny, State of Pennsylvania, have invented a certain newand useful Improvement in the Manner of Constructing the Keepers ofLocks and Latches Having Blunt or Round Ended Spring-Bolts; and I dohereby declare that the following is an exact and full description of myinvention, reference being had to the accompanying drawings and to theletters of reference marked thereon.

The nature of my invention consists in giving to the front or face ofthe keeper such shape and configuration that it shall present to theprotruding bolt while the door is being closed a concave line of contactor a curved incline plane.

To enable others skilled in the art to construct my improved keeper Iwill proceed to describe its construction and operation.

Figure 1 represents a double faced or reversible lock case and thekeeper in their positions relative to each other when the door isclosed. Fig. 2 represents a section through the two faces of the lockand keeper, the door and the j amb, showing the positions of the lockcase, bolt and keeper at the instant the keeper begins to force back thebolt, the door being in the act of closing.

a, a, Fig. 1, is the case of a double faced lock case.

t, b, Fig. 1, is the keeper.

c is the face of the keeper against which Vthe spring bolt impinges whenthe door is thrown to or closed. It is curved from its apex to its basetoward the edge of the door, so that the inclined plane is of thegreatest declination at the top and gradually decreases as it descends.

e, Fig. 2, shows the curve or concavity of the face of the keeper insection.

d, Fig. 2, is the spring bolt represented as having just come in contactwith the keeper at the steepest part of its inclined plane, and hereinis the essence of my invention. The ordinary beveled keeper presents tothe bolt under similar circumstances an inclined plane of uniform gradeand .the leverage which impels the bolt backward into the case is thesame at all points. Now it is clear that a force barely sufiicient tokeep the bolt in motion when started back into the lock case will not besufficient to overcome its inertia and start it in motion, especially ifthere be much friction between the moving parts. My improvement isdesigned with reference to this diliculty, which it efectually obviatesby presenting a very steep incline at the first contact of the bolt. Theobject of the curvature is to accomplish this without making the face.to project to an inconvenient and expensive extent, which it would do ifthe inclination were the same throughout that it is at the top.

g g, Fig. 2, is the lock case in fragment.

x x, Fig. 2, is the door on which the lock is secured.

o, Fig. 2, is the rabbet into which the door shuts.

h is the jamb on which the keeper is secured.

Other parts of the lock and its relations are similar to ordinary locksand need no description.

Having thus fully described my invention, its construction andoperation, I claim as my invention and desire to secure by LettersPatent- The use and employment in combination with a blunt or roundended latch bolt in a double faced or reversible lock case, of a keeperthe face of which is curved or made concave in the manner substantiallydescribed and set forth.

ANDW. PATTERSON.

Witnesses:

C. B. BARR, T. B. ATTERBURY.

